This specification relates to detecting leaks in a feedthrough device, for example, in a fuel injector system. Electro-mechanical fuel injectors are controlled by electrical signals carried by conductors that extend from a low pressure environment into a high pressure zone. The high pressure zone contains a combustible fuel mixture. To prevent the combustible fuel mixture from leaking to the environment, a feedthrough provides a seal around the conductors at the interface where the conductors enter the high pressure zone.
Some conventional feedthroughs include groups of soldered, crimped, or otherwise connected wire strands, with each group of wire strands contained within a solid conductor that is sealed on its outer diameter. A nonconductive body around the conductors seals the conductors relative to each other and ensures insulative spacing between the conductors. When the feedthrough is installed in a fuel injector system, an O-ring seals around the nonconductive body of the feedthrough.